A breakdown of the bond between the fiberglass and foam of a surfboard where the fiberglass gets divided from the foam. Typically triggered by water leaking in below the fiberglass because of a ding of other crack of the waterproof bond. In addition, may also be induced by the surfboard being subjected to extreme heat like being left inside a a hot automobile. This will likely lead to the foam shrinking marginally away from the fiberglass bond. Delaminations really should be repaired quickly as they will disperse and the surfboard durability will be destabilized considerably.